1. Field of the Invention
This invention belongs to the field of agricultural chemistry, and provides a superior process for preparing a series of isoxazolyl imidazolidinones, which are known herbicides, as taught by Lavanish in U.S. Pat. No. 4,268,679.
2. State of the Art
The compounds prepared by the present invention are all taught by Lavanish, who disclose their synthesis by several process variations. One process (columns 19-20 of the patent) proceeds by the cyclization of a substituted isoxazolylurea, where the urea moiety terminates in a dialkyl acetal. That compound was cyclized at elevated temperature in aqueous acid, which process is quite different from the present oxidation of an allylurea with ozone followed by reduction, which provides very excellent yields of relatively pure products.